Method of making a templating agent

ABSTRACT

A method for preparing 1-adamantyltrimethylammonium methylcarbonate or N,N-dimethyl-3,5-dimethylpiperidinium methylcarbonate is disclosed. The method comprises reacting dimethyl carbonate and 3,5-dimethylpiperidine or a 1-adamantylamine compound and in the presence of water in a sealed vessel at a temperature of from 80 to 200° C. The 1-adamantylamine compound is 1-adamantylamine, 1-adamantylmethylamine, or mixtures thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.14/471,737, filed Aug. 28, 2014, allowed on Dec. 18, 2015, and claimspriority benefit of U.S. Provisional Patent Application No. 61/870,973,filed Aug. 28, 2013, the disclosures of which are incorporated herein byreference in their entireties for all purposes.

FIELD OF THE INVENTION

The invention relates to a method for preparing1-adamantyltrimethyl-ammonium methylcarbonate andN,N-dimethyl-3,5-dimethylpiperidinium methylcarbonate.

BACKGROUND OF THE INVENTION

1-Adamantyltrimethylammonium hydroxide andN,N-dimethyl-3,5-dimethylpiperidinium methylcarbonate are useful as atemplating agents in the production of zeolites. A standard route toprepare ammonium salts of organic amines, such as1-adamantyltrimethylammonium hydroxide, includes an alkylation step inwhich the organic amine is reacted with an alkylating agent such asdialkyl sulfates or methyl iodide. For example, U.S. Pat. No. 8,252,943discloses a process for preparing ammonium compounds by reactingcompounds containing a double-bonded nitrogen atom with a dialkylsulfate with participation of both alkyl groups of the dialkyl sulfateand, if appropriate, subjecting the resulting ionic compound containingsulfate anions to an anion exchange. Likewise, U.S. Pat. No. 8,163,951teaches a process for preparing quaternary ammonium compounds, whichcomprises reacting compounds comprising an sp³-hybridized nitrogen atomwith a dialkyl sulfate or trialkyl phosphate and subjecting theresulting ammonium compound to an anion exchange. U.S. Pat. Appl. Pub.No. 2012/0010431 discloses a process for preparing1-adamantyltrimethylammonium hydroxide that comprises reacting1-adamantyldimethylamine with dimethyl sulfate to give1-adamantyltrimethylammonium sulfate, which is then subjected to anionexchange with an ion exchanger loaded with OH ions. In addition, U.S.Pat. No. 4,859,442 describes at Example 1 the preparation of1-adamantyltrimethylammonium hydroxide by alkylation of 1-adamantylaminewith methyl iodide, followed by ion exchange of the iodide anions withan ion exchange resin. U.S. Pat. No. 5,645,812, likewise, teaches thepreparation and use of a N,N-diethyl-3,5-dimethylpiperidinium hydroxidetemplating agent.

In addition, U.S. Pat. No. 6,784,307 teaches a method of preparingquaternary ammonium alkylcarbonates (such as quaternary ammoniummethocarbonates), quaternary ammonium bicarbonates, and quaternaryammonium carbonates by reaction of the corresponding tertiary amineswith a cyclic carbonate and methanol. Zhuoqun Zheng et al. in Adv.Synth. Catal. 2007, 349, 1095-1101 and Chinese Pat. Appl. No. CN1948268describe a process for preparing quaternary salts from amine salts anddimethyl carbonate in the presence of ethyl methyl imidizolium salts ascatalysts. The same authors describe the quaternization of amine saltswithout a catalyst in Chinese Pat. No. CN101245019.

As with any chemical process, it is desirable to attain still furtherimprovements in processes for preparing 1-adamantyltrimethyl-ammoniummethylcarbonate and 1-adamantyltrimethyl-ammonium hydroxide. We havediscovered a new method to produce 1-adamantyltrimethyl-ammoniummethylcarbonate with a high yield.

SUMMARY OF THE INVENTION

The invention is a method for preparing 1-adamantyltrimethylammoniummethylcarbonate or N,N-dimethyl-3,5-dimethylpiperidiniummethylcarbonate. The method comprises reacting dimethyl carbonate and a1-adamantylamine compound or 3,5-dimethylpiperidine in the presence ofwater in a sealed vessel at a temperature of from 80 to 200° C. The1-adamantylamine compound is 1-adamantylamine, 1-adamantylmethylamine,or mixtures thereof.

DETAILED DESCRIPTION OF THE INVENTION

The method of the invention comprises reacting dimethyl carbonate and a1-adamantylamine compound or 3,5-dimethylpiperidine in the presence ofwater in a sealed vessel at a temperature of from 80 to 200° C.

The 1-adamantylamine compound or 3,5-dimethylpiperidine is reacted withdimethyl carbonate to produce 1-adamantyltrimethylammoniummethylcarbonate or N,N-dimethyl-3,5-dimethylpiperidinium methylcarbonatein a combined methylation/quaternization step. The 1-adamantylaminecompound is 1-adamantylamine, 1-adamantylmethylamine, or mixturesthereof.

Preferably, the reaction of 1-adamantylamine, 1-adamanylmethylamine or3,5-dimethylpiperidine with dimethyl carbonate in the presence of wateris performed at elevated temperature and pressure, for example in anautoclave. In addition to dimethyl carbonate, the 1-adamantylaminecompound or 3,5-dimethylpiperidine, and water, the reaction may beperformed in the presence of other solvents such as methanol or otheraprotic solvents inert to the reaction conditions, but additionalsolvents are not required. Preferably, the reaction step involves mixingthe 1-adamantylamine compound or 3,5-dimethylpiperidine with water,followed by the addition of dimethyl carbonate.

Typically, the reaction mixture containing 3,5-dimethylpiperidine or the1-adamantylamine compound, water and dimethyl carbonate is heated at atemperature of about 80° C. to about 200° C. for a period greater thanabout 0.25 hours (preferably less than about 48 hours) in a sealedvessel under autogenous pressure. Alternately, the vessel may be fittedwith a device to limit the rise in pressure by venting some of thecarbon dioxide produced. More preferably, the reaction mixture is heatedat a temperature range from about 100° C. to about 175° C., mostpreferably from about 120° C. to about 160° C. The reaction temperaturemay also be increased over the course of the reaction. The reaction ispreferably performed from 1 to 24 hours. The reaction may be carried outin a batch, continuous, or semi-continuous manner using any appropriatetype of reaction vessel or apparatus such as a stirred vessel or CSTRreactor.

Preferably, the molar ratio of dimethyl carbonate: 1-adamantylaminecompound or 3,5-dimethylpiperidine is in the range of 5 to 20, morepreferably the molar ratio is in the range of 8 to 14.

The presence of water is required for the methylation/quaternizationreaction to occur. Preferably, the molar ratio of water:the1-adamantylamine compound or 3,5-dimethylpiperidine is in the range of 1to 4.

After the reaction is complete, the 1-adamantyltrimethylammoniummethylcarbonate or N,N-dimethyl-3,5-dimethylpiperidinium methylcarbonateis preferably recovered. Suitable recovery methods include filtrationand washing, rotary evaporation, centrifugation, and the like. In apreferred embodiment, the reaction mixture is cooled to ambienttemperature and a portion of the reaction mixture (preferably reducingthe reaction volume by greater than 25%) is stripped to remove anymethanol that might have formed. The remaining slurry may be furthercooled to a temperature less than 10° C., and the1-adamantyltrimethylammonium methylcarbonate orN,N-dimethyl-3,5-dimethylpiperidinium methylcarbonate product isolatedby filtration and then washed with cold dimethyl carbonate or acetone.The white crystalline product can be further dried under vacuum toproduce the final 1-adamantyltrimethylammonium methylcarbonate orN,N-dimethyl-3,5-dimethylpiperidinium methylcarbonate.

Preferably, the 1-adamantyltrimethylammonium methylcarbonate orN,N-dimethyl-3,5-dimethylpiperidinium methylcarbonate is further reactedwith calcium hydroxide in the presence of water to produce1-adamantyltrimethylammonium hydroxide orN,N-dimethyl-3,5-dimethylpiperidinium hydroxide. In addition to water,the reaction may be performed in the presence of other solvents, such asalcohols, but additional solvents are not required. At least one moleequivalent of water is utilized in comparison to the1-adamantyltrimethylammonium methylcarbonate orN,N-dimethyl-3,5-dimethylpiperidinium methylcarbonate, but preferably anexcess of water is used. A molar excess of calcium hydroxide to1-adamantyltrimethylammonium methylcarbonate or N,N-dimethyl-3,5-dimethylpiperidinium methylcarbonate is preferred, morepreferably the molar ratio of calcium hydroxide:1-adamantyltrimethylammonium methylcarbonate orN,N-dimethyl-3,5-dimethylpiperidinium methylcarbonate is in the range of1.05 to 1.75.

Preferably, the reaction mixture of calcium hydroxide and1-adamantyltrimethylammonium methylcarbonate (orN,N-dimethyl-3,5-dimethylpiperidinium methylcarbonate) is heated at anelevated temperature, preferably at reflux. The methanol produced isslowly distilled off until the vapor temperature is constant.

The 1-adamantyltrimethylammonium methylcarbonate orN,N-dimethyl-3,5-dimethylpiperidinium methylcarbonate itself may also beused as a templating agent for the production of zeolites, but it ispreferably to utilize the 1-adamantyltrimethylammonium hydroxide or N,N-dimethyl-3,5-dimethylpiperidinium hydroxide. Zeolite synthesis iswell-known in the art, and generally consists of reacting a siliconsource, an aluminum source, (plus other metal sources if desired), andthe templating agent at a temperature and for a time sufficient to forma molecular sieve. Typical silicon sources include colloidal silica,fumed silica, silicon alkoxides, and mixtures thereof. Typical aluminumsources include sodium aluminate, aluminum hydroxide, aluminumisopropoxide, aluminum sulfate, and aluminum nitrate.

The zeolite synthesis is typically performed in the presence of water.Other solvents such as alcohols may also be present. After the reactionmixture is formed, it is reacted at a temperature and a time sufficientto form a molecular sieve. Typically, the reaction mixture is heated ata temperature of about 100° C. to about 250° C. for a period greaterthan about 0.25 hours (preferably less than about 96 hours) in a sealedvessel under autogenous pressure. The reaction may be carried out in abatch, continuous, or semi-continuous manner using any appropriate typeof reaction vessel or apparatus such as a stirred vessel or CSTRreactor. After the reaction is complete, the zeolite is recovered.

As synthesized, the zeolite will contain some of the templating agent inthe pores. Any suitable method to remove the templating agent may beemployed. The template removal is typically performed by a hightemperature heating in the presence of an oxygen-containing gas, such asair or a mixture of oxygen and an inert gas. Preferably, the zeolite isheated at temperatures greater than 250° C. to remove the templatingagent. Temperatures of from about 275° C. to about 800° C. arepreferred.

The following examples merely illustrate the invention. Those skilled inthe art will recognize many variations that are within the spirit of theinvention and scope of the claims.

Example 1 1-Adamantyltrimethylammonium Hydroxide Preparation

Adamantyltrimethylammonium Methylcarbonate Synthesis:

1-Adamantamine (37.7 g, 0.25 mol), dimethylcarbonate (300 mL, 3.5 mol)and water (9 mL, 0.5 mol) are combined in an autoclave and heated to150° C. for 10 hours. The autoclave is fitted with a pressure release sothat the maximum pressure attained is 10 bar (1000 kPa). On cooling, thecontents of the vessel are stripped completely dry and the residueslurried with 150 mL of acetone and cooled, filtered and washed with alittle cold acetone. Drying gives a yield of 54 g (80.6%) H-NMR analysisis consistent with the structure.

1-Adamantyltrimethylammonium Hydroxide Synthesis:

Adamantyltrimethylammonium methylcarbonate (383 g, 1.42 mol) is added towater (1000 mL), followed by addition of calcium hydroxide (148 g, 2.0mol). This addition is exothermic. The reaction mixture is then heatedto reflux and the methanol produced is slowly distilled off until thevapor temperature is constant. The reaction mixture is then cooledslowly to 10° C. and the precipitated calcium carbonate and excesscalcium hydroxide are filtered off on a Nutsche filter. The filter cakeis washed with water (200 mL) and both the mother and wash filtrates arecombined. The 1-adamantyltrimethylammonium hydroxide product yield is1284 grams of solution with assay 20.2% w/w.

Example 2 1-Adamantyltrimethylammonium Hydroxide Preparation

1-Adamantamine (30.2 g, 0.2 mol), dimethylcarbonate (250 mL), methanol(25 mL), and water (4.5 g, 0.25 mol) are combined in an autoclave andheated at 140° C. for 8 hours. The vessel is cooled and the contentsstripped to dryness. Crude yield is 51 g (94.6%). This crude1-adamantyltrimethylammonium methylcarbonate material is used directlyin the next step.

The crude methylcarbonate salt from the previous reaction is dissolvedin 150 mL of deionized water, and a small amount of solid is filteredoff and washed with a further 25 mL of deionized water. The filtrate isthen transferred to a flask set up for distillation, and 21 g of calciumhydroxide is added. The mixture is heated to boiling and methanol and asmall amount of steam and volatile organic material is distilled out. Oncooling, the insoluble calcium salts are filtered off and washed with alittle deionized water. The 1-adamantyltrimethylammonium hydroxidesolution product yield is 204 g with an assay of 16.0% (77% overall).

Example 3 N,N-Dimethyl-3,5-Dimethylpiperidinium MethocarbonatePreparation

3,5-Dimethylpiperidine (28.2 g, 0.25 mol), dimethylcarbonate (300 mL),and water (9 g, 0.5 mol) are combined in an autoclave and heated to 150°C. for 6 hours. The autoclave is fitted with a pressure release so thatthe max pressure attained is 6 bar (600 kPa). The contents of the vesselare stripped to dryness, then 150 mL of acetone is added the mixture,stirred at 10° C., and then filtered to give the desiredN,N-dimethyl-3,5-dimethylpiperidinium methylcarbonate salt (38 g, 70%).H-NMR analysis is consistent with the structure. This material may beconverted to the hydroxide salt with calcium hydroxide as described inExample 1.

Although the method of the invention successfully produces1-adamantyltrimethyl-ammonium methylcarbonate andN,N-dimethyl-3,5-dimethylpiperidinium methylcarbonate, the method issurprisingly less successful when applied to primary monoalkyl aminessuch as n-dodecylamine or benzylamine, giving a variety of byproductsand only low yields of the desired quaternary methylcarbonate salts.

I claim:
 1. A method for preparing 1-adamantyltrimethylammoniummethylcarbonate, comprising reacting 1-adamantylamine compound anddimethyl carbonate in the presence of water in a sealed vessel at atemperature of from 80 to 200° C., wherein the 1-adamantylamine compoundis selected from the group consisting of 1-adamantylamine,1-adamantylmethylamine, and mixtures thereof.
 2. The method of claim 1wherein the molar ratio of dimethyl carbonate: the 1-adamantylaminecompound is in the range of 5 to
 20. 3. The method of claim 1 whereinthe molar ratio of dimethyl carbonate: the 1-adamantylamine compound isin the range of 8 to
 14. 4. The method of claim 1 wherein the molarratio of water:the 1-adamantylamine compound is in the range of 1 to 4.5. The method of claim 1 wherein the reaction of the 1-adamantylaminecompound with dimethyl carbonate is performed at a temperature in therange of 120-160° C.
 6. The method of claim 1 wherein the1-adamantylamine compound is 1-adamantylamine.
 7. The method of claim 1further comprising reacting the 1-adamantyltrimethylammoniummethylcarbonate with calcium hydroxide in the presence of a water toproduce 1-adamantyltrimethylammonium hydroxide.
 8. The method of claim 7wherein the molar ratio of calcium hydroxide:1-adamantyltrimethylammonium methylcarbonate is in the range of 1.05 to1.75.
 9. The method of claim 7 wherein the reaction of1-adamantyltrimethylammonium methylcarbonate with calcium hydroxide inthe presence of water is performed at reflux.